Basically it's a buffer for storing information in order to help reduce bottlenecks.

SSD's/HDD's are the solution to very large storage, but they're comparatively slow to RAM. Ram is much faster, so information that will need to be processed, or if space permits, might be processed, gets stored there.

The advantage of more ram, to a point is that your PC will basically be able to bite off more to chew at a time, without having to go back to the SSD/HDD for more data. Going to the HDD/SSD is slow by comparison.

Desktop: has 2x 16GB = 32 GB Corsair Vengeance LPX DDR4-3000. This is my VR build so I wanted to make sure that it more then enough RAM so i could run VR via my HTC Vive at a min of 2160*1200 @ 90hz and on my monitor 3840X2160 @ 60hz. Next purchase will be a 4k monitor that runs at 120hz plus (the new ROG Predators look absolutely stunning).

Its also my backup work machine for running ultra big chunky datasets (like 1GB plus with 12-15 calculations on 5-10 million values)

I currently have 16 GB of Corsair Vengeance DDR4 in my gaming PC. Got it as a pair. I have the same set in my Linux PC, and I'm thinking of cutting that down to a pair of 4, and moving the other 16 to my gaming PC.

I have 4x2GB sticks (8GB) of DDR2 ECC Ram. It can run 16GB but I have not seen the need yet for what I do.

The system I have is older server grade hardware running W10 Pro 64 bit. It is an older Sun Microsystems Ultra 24 with an Intel x38 chipset board. Has lots of cool features like Intel RAID and a Sun storage backplane for 4 drives which includes SAS capability (which I will never need). It is running a version of American Megatrends bios which Sun did some cool stuff with that for its time is really cool work with even now.